The roman numeral corresponding to 1,000 is M.
If we think purely in terms of the strokes comprising M, then each of "/" and "\" have the same length and are smaller than "|" and accordingly may qualify as smaller of the "parts"
If we think purely in terms of numbers, then since V is the roman numeral for 5, and "I" is the roman numeral for 1, and the "I" part (two vertical straight lines) of M is numerically smaller than the "V" part ( that is the lines joining the two vertical lines), we can assert that each of the "I" corresponds to the smaller "part" of 1,000.
Obviously, these are not the precise answers to the given problem as presented, since only the "smaller" part(s), and not the smallest part is presented in each, but this does serve to a proposed answer to a modification of the same.
Edited on June 28, 2008, 7:17 am